After a year of sitting on my shelf, I finally got off my arse and installed the CH and EWDS.
One reason it’s taken me so long (other than pure laziness) was making the choices of where to mount the CH buzzer and the EWDS “Brain” as well as how and where to move the oil sensor cluster.
That took the most time/thought investment.

Anyway, as my Grandfather always said, “The hardest part of any job is starting”
So, I dove in and got started and just finished it this morning.

A big challenge was “sealing” all of the new fittings so I wasn’t leaking water or oil.
Took some time getting it right with everything lining up, but finally success.
The Oil “rig” was the hardest. I copied Neil's bulkhead setup a little and jury-rigged some on my own.

The little bit of re-wiring was also time-consuming.
I wanted all wires out of the way and not just dropping down to the sensors.
I installed a GROUND buss bar on the port side to get things cleaned up and not having extra ground wires.

Fired it up and tested all the fittings. No leaks and all of the warning lights and buzzer alarmed when they’re supposed to.

During development many difficult decisions had to be made to produce a system that would be meaningful in all situations but still avoid false alarms. For the coil input voltage parameter we have engines with no resistors, engines with modest resistors and yet others with big resistors. We have engines with 13.8V alternator output, many with 14.0~14.2V output and at least one with 14.8V output. Then we have wiring system voltage drop, different on every boat and some within ABYC specs, many not. Given all that, pick a meaningful trip point voltage. You can see the difficulty.

Not wanting to take a stab at a voltage picked out of thin air we used the excellent voltage testing done by Thatch as an adjunct to the 'Rule of 2011', the electronic ignition study performed in that year. He tested and actually measured the coil input voltage point where engine performance degraded.

The EWDS gives a warning prior to failure (the 'EW' in the acronym) but the real benefit of the system is how it aids the troubleshooting process by telling you where the failure occurred (the 'D' in the acronym). Imagine your engine RPM drops unexpectedly. A glance at the EWDS display shows the coil light illuminated. You can focus your efforts on the ignition wiring and forget about everything else.

I got the temp/oil/flow sensor package installed but still saving my nickles for the EWDS. It did already alert me to a temperature problem last month. (Disintegrated HX cap/loss of fluid.)

In another thread, someone was showing how he rigged up an indoor-outdoor thermometer to to give him a cockpit reading of his stuffing box/packing nut temperature. Wow. I was perfectly content with not knowing that parameter... until now :roll eyes:

I got the temp/oil/flow sensor package installed but still saving my nickles for the EWDS. It did already alert me to a temperature problem last month. (Disintegrated HX cap/loss of fluid.)
(Autocorrect tells me that I'm saving my pickles. That seems really weird...)

Something about the "coil" warning feature doesn't quite sit right with me. As I understand it the system gives warning when voltage at coil+ drops below 9 volts. If that is so, then what is really being monitored is the ignition delivery to coil +, not the coil itself.

then what is really being monitored is the ignition delivery to coil +, not the coil itself.

That's correct Hanley, just like the fuel pressure monitor. Without sufficient fuel pressure the carb doesn't stand a chance of proper operation. Without sufficient voltage, the healthiest coil in the world won't function properly. Nobody ever suggested we were monitoring coil function. I'm glad you mentioned it so we could clear up any misconceptions.

Please remember that knowing what isn't a problem can be as valuable as what is. If you had an unexpected RPM reduction and none of the EWDS lights illuminated you would know you had sufficient voltage to the coil and sufficient fuel pressure to the carb. You don't need to waste time investigating those systems.

The EWDS therefore is only as good as the operator's knowledge of systems. If the "coil" alarm is triggered what is really be said is that insufficient voltage is being delivered to coil+. It is the operator's duty to troubleshoot back to the ignition or OPSS or even beyond. As for fuel pressure, the system only advises of low pressure at the carb, but many problems lie downstream especially at the main jet. Only the fuel ratio gauge can detect that. The temp feature can prevent an overheating event. Check. The flow feature can prevent a disaster in the water lock or exhaust hose. Double check. The oil feature is too late for me; if pressure is below 7 psi my OPSS shuts the engine down pronto. The EWDS system coupled with operator knowledge is definitely a winner

The trip point for the voltage If I remember is 9 volts. In the interest of learning more about this, I did read Neil's response about a lot of different systems and trying to have this fit as many as posable. Why 9 volts. I've read other coil and alternator posts that 12 volts in a system is considered low and should be investigated. Can this engine start below 12 volts.

Trying to learn as much as I can. Have been wading through a lot of old posts to learn. Obviously from my question I'm not quite there yet.

Some boats are wired to provide less than system voltage to the coil, thus an alarm set at 12 volts might be just permanently on.
In other news, my last car, a BMW, had a "fake" temperature gauge run by the ECU. It sat right in the middle of the range if the engine was anywhere near normal temps and suddenly went all the way to the red zone if it got 1 degree past the overheat limit. You had no trend information at all. OTOH it had a warning light. My current Mazda has a "real" temp gauge but no warning light. A Cessna 172 I was flying had no warning lights at all and the manual said to disregard a 0 oil pressure reading if the oil temp was not too high. Their theory was correct if the oil level was low the oil would get hot. Their theory was very wrong if the oil pump failed because non-circulating oil does not get hot
Thus our unplanned arrival in a farmer's field. It pays to know your systems!

Quote:

Originally Posted by azazzera

The trip point for the voltage If I remember is 9 volts. In the interest of learning more about this, I did read Neil's response about a lot of different systems and trying to have this fit as many as posable. Why 9 volts. I've read other coil and alternator posts that 12 volts in a system is considered low and should be investigated. Can this engine start below 12 volts.

Trying to learn as much as I can. Have been wading through a lot of old posts to learn. Obviously from my question I'm not quite there yet.

Trying to learn as much as I can. Have been wading through a lot of old posts to learn. Obviously from my question I'm not quite there yet.

We're here to help the best we can and there's no shame in asking questions, not on this forum.

Quote:

Originally Posted by azazzera

Why 9 volts? I've read other coil and alternator posts that 12 volts in a system is considered low and should be investigated. Can this engine start below 12 volts.

We chose 9 volts (approximate) for the reason presented in the second paragraph of post #7 in this thread. Tom Thatcher performed some critical and invaluable real world testing and actually measured the coil input voltage where engine performance declined, it was a hair below 9 volts. Now, there are a few factors that affected his measurement such as RPM and dwell as both pertain to coil saturation but even so, the information was incredibly important. As stated in post #7, using actual test data to design a trip point seemed far better than pulling a value out of thin air.

For the record, even though it has been suggested occasionally, we don't make up our own target values. This trip point was the result of solid testing. The 4 amp ignition system maximum described in the 'Rule of 2011' was a specification from the manufacturer of MMI's electronic ignition product. I'll admit the 15% safety margin applied in the Rule of 2011 was ours but subject to change after subsequent testing if the testing lead us in that direction. It didn't.

As for the A-4 being able to start below 12V, sure. I bet it starts below 12V every time you push the start button. The ~130 amp starter load surging through typically smallish cable for that load imparts voltage drop below the battery voltage at rest. The alternator doesn't contribute anything until the RPM's come up so no help there.

The trip point for the voltage If I remember is 9 volts. In the interest of learning more about this, I did read Neil's response about a lot of different systems and trying to have this fit as many as posable. Why 9 volts. I've read other coil and alternator posts that 12 volts in a system is considered low and should be investigated. Can this engine start below 12 volts.

Trying to learn as much as I can. Have been wading through a lot of old posts to learn. Obviously from my question I'm not quite there yet.

If you install a digital voltmeter in a location where you can see it while cranking you will see around 10 volts until the engine is running. This is sufficient voltage to run the Atomic 4, provided it is actually being delivered to coil+.

After doing a quick calculation with what my coil voltage is seeing and its ohms are I understand a bit more about how someone with a higher output alternator would need to limit the voltage to the coil to meet the 4 amp limit. Haven't done an official reading at coil post just what coming from alternator from an old analog meter but playing with the numbers fills the gaps in for me. More reading. Little bites from the tree of knowledge. Thanks again for the info and patience. Now stop bothering me so I can read.